💬 Multi-Sensor: Temp/Humidity/PIR/ Leak/Magnet/Light/Accel

[Nca78]

@NeverDie said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Also, since the back of it is almost entirely ground plane anyway, it seems ripe for using a smaller profile CR2032 battery holder, such as: https://www.digikey.com/scripts/DkSearch/dksus.dll?Detail&itemSeq=243085164&uq=636456618668326452

Not only would it be thinner, but maybe (?) I could also shave a few millimeters off the PCB diameter .

So, yeah, I'm definitely open to improving the design.

Your link is broken, looks like a search result and not a product page ;)

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Your link is broken, looks like a search result and not a product page

Thanks for letting me know. Not sure what's going wrong. When I click on the link, it takes me right there.

Hmmmmm... The manufacturer's part number is "BK-913-TR". Try entering that into the search field on digikey. It's the one for $0.38.

[NeverDie]

I've just now uploaded Version 3, which fixes an overlap issue in Version 2 between the 10-pin connector and the optional Si7021/BME280. AFAIK, everything should work now.

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Then there's the DRV5032 from TI that had the lowest power consumption a few month ago when I bought it, it's 0.5$ on Arrow and needs only 0.54uA in the FB (5Hz) version
https://www.arrow.com/en/products/drv5032fbdbzr/texas-instruments

Thanks for the links. I think I'll first try putting the Version 3 TH sensor into the deadbolt cavity and see what kind of range I get with that. It might be seriously impaired, since it will have metal on 2-3 sides. If I'm getting usable signal though at a decent range, then at that point I'll look into adding the DRV5032 to the board.

[NeverDie]

Yesterday I received an CR2477 button cell holder, and it appears that it can easily substitute for the CR2032 in the BOM: the pins seem very much aligned.

https://www.digikey.com/product-detail/en/mpd-memory-protection-devices/BH1000G/BH1000G-ND/140383

Therefore, if you want a battery with roughly 4x the mah and which can also support a higher current drain than a CR2032, it's a good option. :)

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Your link is broken, looks like a search result and not a product page

Try this: https://www.digikey.com/product-detail/en/mpd-memory-protection-devices/BK-913-TR/BK-913-CT-ND/6200236

[NeverDie]

I just now uploaded some demo source code that will make the node into a proper MySensors temperature node.

[NeverDie]

I just now uploaded the Version 4 files. The new design uses the more compact CR2032 battery holder discussed above. :)

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Also, what about moving the led to the center next to its resistor, it would leave enough space to squeeze in a SOT 23 ultra low power hall sensor and it's 100nF capacitor.

Yes, with the Version 4 design serving as the basis, I think there will be enough room to do this.

I'd also like to add a light sensor of some kind: something that will trigger an interrupt when, say, a refrigerator light goes on or off (for the case where the temperature node is in a refrigertor or freezer). Do you have any particular suggestions for that? A simple photoresistor, or would there be something better (lower current)?

[Nca78]

Low current light sensor with interrupt, you have OPT3001 and MAX44009. MAX44009 has the lowest power but it doesn't have the same availability (not on Arrows for example).
If you're planning to use it from breakout board (as they are boath really tiny) then MAX44009 is the best choice as it's cheaper on AliExpress.

If you want one that you can solder by hand you can check VEML7700, it's cheap, has low power consumption (2uA) if you use a low refresh rate. But it goes only down to 2.5V so you will lose a bit of the capacity of the button cell, and it has no interrupt pin.

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

Also, what about moving the led to the center next to its resistor, it would leave enough space to squeeze in a SOT 23 ultra low power hall sensor and it's 100nF capacitor.

Done. I just now uploaded Version 5, which has the TI hall effect sensor.

[NeverDie]

@Nca78 said in 💬 CR2032 Small Wireless Temperature-Humidity Sensor:

MAX44009 has the lowest power but it doesn't have the same availability (not on Arrows for example).
If you're planning to use it from breakout board (as they are boath really tiny) then MAX44009 is the best choice as it's cheaper on AliExpress.

Looks as though if I add just one more header pin, then I can use this board:
https://www.aliexpress.com/item/MAX44009-Ambient-Light-Sensor-Module-with-4P-Pin-Header-Module/32729312303.html?spm=2114.search0204.3.47.XOZuu8&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_10151_10344_10068_10130_10345_10324_10342_10547_10325_10343_10546_10340_10341_10548_10545_10541_10562_10084_10083_10307_10178_10060_10155_5680017_10154_10056_10055_10539_10537_10312_10536_10059_10313_10314_10534_10533_100031_10103_10073_10102_10557_10558_10142_10107-10178,searchweb201603_25,ppcSwitch_4_ppcChannel&btsid=ca20f561-ad43-4536-b09f-7856bf41fbb2&algo_expid=0601cfd8-6d07-4336-aefc-c06bc54166ac-2&algo_pvid=0601cfd8-6d07-4336-aefc-c06bc54166ac
That way I could capture the interrupt.

[NeverDie]

OK, I just now uploaded the files for Version 6, which does just that. Unless someone can think of another sensor to add, I think this will be the final version (unless errors are discovered). :)

[ghiglie]

I'm quite a noob, but totally with the NRF. Interesting PCB, I'll try asap to put a sensor together!

[NeverDie]

I made one last change to add water leak detection to it. I just now uploaded the version 7 files. :)

[NeverDie]

I have the Version 1 design now working with the si7021 breakout board that I got from Aliexpress. Note that if you use these breakout boards, remember to remove the voltage regulator and solder bridge across the two pins as shown in the photo below:

This is because the coin-cell voltage is already in the desired range, and so there's no need for further voltage reduction.

[Toyman]

Is v7 already for CR2477? BOM still mentions CR2032

[NeverDie]

@Toyman said in 💬 Small Wireless Temp/Humidity Leak/Magnet/Light/Accel Sensor:

Is v7 already for CR2477? BOM still mentions CR2032

If I had kept the same button cell holder as some of the earlier version it would be. However, I switched to a narrower profile battery holder in the BOM (which benefits the leakage sensor part of the design). Not sure if an equivalent CR2477 holder is still available with the new design. Haven't checked. When I brought up the possibility of a CR2477 earlier, it didn't seem to generate much enthusiasm at the time. So, I took that to mean most people weren't really interested.

[krisha]

Nice project!

What about adding two resistors to measure and send the battery level as well?

[NeverDie]

@krisha said in 💬 Small Wireless Temp/Humidity Leak/Magnet/Light/Accel Sensor:

What about adding two resistors to measure and send the battery level as well?

not needed. You can measure the battery voltage without a divider.